Trump rally shooter searched on phone for dates of Democratic National Convention in Chicago

CHICAGO -- Thomas Matthew Crooks, the suspected gunman in the assassination attempt on Donald Trump last Saturday, searched on his phone for the dates of the former president's rally in Butler, Pennsylvania, and for dates of the Democratic National Convention in Chicago, sources familiar with the investigation told ABC News.

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Crooks also searched on his phone for images of both the former president and current president, sources said.

The suspect's phone search history revealed no indication of his political views.

READ MORE | Secret Service spotted shooter on roof 20 minutes before gunfire erupted at Trump rally

The Chicago Police Department called a press conference Monday in response to all the questions that have inevitably surfaced surrounding security for the upcoming Democratic National Convention after an assassination attempt on former president Donald Trump over the weekend.

The Secret Service will be in charge of security of what is being referred to as the hard perimeter, which is the inside of the United Center and the immediate area surrounding it.

So not only is it CPD's job to ensure that all the planned protests go off peacefully, but they do have responsibility, in conjunction with the Secret Service, for manning and securing the rooftops of all the buildings outside of the hard perimeter which may have a line of sight to the United Center.

CPD Supt. Larry Snelling reiterated that planning for this event has been going on for over one year, and that planning includes preparations for every scenario.

Snelling also said that he is in contact with his counterparts in Milwaukee so that any lessons from the RNC this week can be applied in Chicago.

One thing to note is that it is still not clear where the hard and soft perimeters will be. The Secret Service is expected to release the exact boundaries in the coming weeks.

ABC7 Chicago contributed to this report.